From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F144C6FA82 for ; Fri, 9 Sep 2022 12:08:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230108AbiIIMIy (ORCPT ); Fri, 9 Sep 2022 08:08:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230483AbiIIMIi (ORCPT ); Fri, 9 Sep 2022 08:08:38 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2C8D13810C for ; Fri, 9 Sep 2022 05:08:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662725316; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0zXr68Ku17TqRx7WZIlisO7PY+izsxHqFvN1+7uz8BY=; b=RHnrB20Z0vzPWl+eBeMd1bOrGahIzevDj5TL4kLpXMQw6+4uZ7ppjYYQRI0FeIdrA+DwVx 2UB89cVs8PTIS9kiTDVORjmQ2uv68JeSHbPG/ysiRnjGUwrinSEFtvODvkX6RPJ1JCpxzL 5Nnl/JaJ+ToPlu24XMxtNN9pG4lKx2s= Received: from mail-io1-f72.google.com (mail-io1-f72.google.com [209.85.166.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-211-InZwhu-POJypt-WQl67BIg-1; Fri, 09 Sep 2022 08:08:34 -0400 X-MC-Unique: InZwhu-POJypt-WQl67BIg-1 Received: by mail-io1-f72.google.com with SMTP id o10-20020a6b5a0a000000b0068aba769d73so1212188iob.4 for ; Fri, 09 Sep 2022 05:08:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:organization:references :in-reply-to:message-id:subject:cc:to:from:date:x-gm-message-state :from:to:cc:subject:date; bh=0zXr68Ku17TqRx7WZIlisO7PY+izsxHqFvN1+7uz8BY=; b=UTxqr6NuT/CNXKper3o9jQPCjkzfPOpoWzJCbdazYSDRrycGJT4wb8gL37/SSoC3/7 pXSMHifDUhXpf6kX4qtootSr3iE8dzTmCu/f6C8Hg/fFO5IvEIDMnw+W3iIvSaQWojov M5JSVLq0LtLeWNDZtTQXeSYT9ncScH3P9NeqgGZMQiez3PG52BmsdbOBMX/riWbqQzEZ YNKhazQl4yBki84YlFp7aAEdp50WCELV9rbsviPiG1SdbntIivHsc9racjHECt+Nb31Y ej/8N6VMhR4JE+2zrTkGKoJvJ1szqkZqMqVEml4UdBLFo3sOFPqcujSk9IKEaBycyQg0 UEsw== X-Gm-Message-State: ACgBeo3qEXi5yUgjy4/06tINZdpgVkwFLEJmcmnnv1WTXUsrgu0hoUVr 8qtwZHa/Bxgrj0dl2USRuV8VzSgI+MMhcqIh8CdhgGAruF+XV3R8ercMrFYWwvK3vEBd4ks79cD 5eMi4jM/Uf+tMWmHuzfyC1PZa X-Received: by 2002:a05:6602:1691:b0:68d:8e03:197b with SMTP id s17-20020a056602169100b0068d8e03197bmr6694185iow.190.1662725314162; Fri, 09 Sep 2022 05:08:34 -0700 (PDT) X-Google-Smtp-Source: AA6agR5iSRx1+fKzoqaDdK1SGGLBKpq8PLWfkyRCyK8z6gMVXMYQAnQZDmTYSNyT4G7AZUQrY+aZ8g== X-Received: by 2002:a05:6602:1691:b0:68d:8e03:197b with SMTP id s17-20020a056602169100b0068d8e03197bmr6694175iow.190.1662725313935; Fri, 09 Sep 2022 05:08:33 -0700 (PDT) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id g15-20020a05663810ef00b00358422fcc7bsm126205jae.120.2022.09.09.05.08.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Sep 2022 05:08:33 -0700 (PDT) Date: Fri, 9 Sep 2022 06:08:32 -0600 From: Alex Williamson To: Linus Torvalds Cc: John Hubbard , David Hildenbrand , Andrew Morton , "kvm@vger.kernel.org" , linux-kernel@vger.kernel.org, Jason Gunthorpe Subject: Re: [GIT PULL] VFIO fix for v6.0-rc5 Message-ID: <20220909060832.17f6607f.alex.williamson@redhat.com> In-Reply-To: References: <20220909045225.3a572a57.alex.williamson@redhat.com> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 9 Sep 2022 07:53:17 -0400 Linus Torvalds wrote: > On Fri, Sep 9, 2022 at 6:52 AM Alex Williamson > wrote: > > > > VFIO fix for v6.0-rc5 > > > > - Fix zero page refcount leak (Alex Williamson) > > Ugh. This is disgusting. > > Don't get me wrong - I've pulled this, but I think there's some deeper > problem that made this patch required. > > Why is pin_user_pages_remote() taking a reference to a reserved page? > Maybe it just shouldn't (and then obviously we should fix the unpin > case to match too). > > Adding a few GUP people to the participants for comments. > > Anybody? Yes, David is working on allocating pages rather than pinning the zero page, however that's going to have some user visible locked memory accounting changes. This isn't the long term solution, it's only meant to close the shared zero page refcount holes we have currently. Thanks, Alex